WASHINGTON, Aug 31 (Reuters) - U.S. emergency officials said on Thursday the plume caused by two explosions at the flood-hit Arkema SA chemical plant in Crosby, Texas, was “incredibly dangerous,” noting officials were still trying to evaluate the hazards.

“Right now, the question is whether or not we can actually get in and assess the full scale of the impact from an environmental standpoint to an infrastructure stand point,” Federal Emergency Management Agency (FEMA) Administrator Brock Long said at a news briefing. “By all means, yes, the plume is incredibly dangerous.” (Reporting by Susan Heavey and David Alexander)